Well... some people like to have sex with more than one person. Some people trust their partners enough that they know they are still loved whilst they shag around. It works better for some people, especially the kinky ones.

If it works for people? Go for it! As long as it's all cool with everyone, I don't see what the issue is. Same as monogamy - be monogamous if you want to be, if your relationship(s) will work better differently, do that. As long as all partners involved know what's going on and are cool with it, kudos.

What? Obviously being in a relationship with someone is different to being **** buddies, it's a whole new level of intimacy, you've made an emotional commitment to that person. In fact, I'd say that open relationships are more of a commitment if anything, as you're trusting that your partner will still want a long-term emotional connection with you despite having physical (maybe emotional too, depending on your agreement) connections with others.

Open relationships are when you want to keep it casual or on a more deeper level (if it's not the whole I'm too horny to keep my pants on half the time) it's about not owning your other partner. The couple in the relationship love each other and trust each other enough and know it - they know that sex and love can be different, and you don't need to chain yourself to each other's genitals to confirm your love for them, or own them to love them.

Or, you want the best of both the single and the couple worlds by having multiple sexy times with different people while kissing and cuddling with someone you're intimate with.